Note: Descriptions are shown in the official language in which they were submitted.
WO 2017/200903 PCT/US2017/032601
Sprung Coupling
Field of the Invention
This invention relates to mechanical pipe couplings for joining pipe elements.
Background
Mechanical couplings for joining pipe elements together end-to-end comprise
interconnectable segments that are positionable circumferentially surrounding
the end
portions of co-axially aligned pipe elements. The term "pipe element" is used
herein 'to
describe any pipe-like item or component having a pipe-like form. Pipe
elements include pipe
stock, pipe fittings such as elbows, caps and tees as well as fluid control
components such as
valves, reducers, strainers, restrictors, pressure regulators and the like.
Each mechanical coupling segment comprises a housing having projections which
extend inwardly from the housing and engage, for example, the outer surfaces
of pipe
elements of various configurations including, for example, pipe elements
having
circumferential grooves. Engagement between the projections and the pipe
elements provides
mechanical restraint to the joint and ensures that the pipe elements remain
coupled even under
high internal pressure and external forces. The housings define an annular
channel that
receives a ring gasket or seal, typically an elastomeric ring which engages
the ends of each
pipe element and cooperates with the segments and the pipe elements to provide
a fluid tight
seal. The segments have connection members, typically in the form of lugs
which project
outwardly from the housings. The lugs are adapted to receive fasteners, such
as nuts and
bolts, which are adjustably tightenable to draw the segments toward one
another.
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Mechanical couplings for grooved pipe elements according to the prior art have
continuous arcuate projections on the segments that engage the outer surfaces
of the pipe
elements which they are joining end to end. These arcuate projections are part
of the segment
structure commonly referred to as the "keys" of the coupling. Thc keys may
engage the outer
surface of pipe element in various configurations including, for example, pipe
element having
circumferential grooves.
The arcuate projections on prior art couplings for grooved pipe elements
typically
have arcuate surfaces with a radius of curvature that is marginally larger
than the radius of
curvature of the outer surface of the pipe element within the groove that it
is intended to
engage. For couplings used with grooved pipe elements, the radii of curvature
of the arcuate
surfaces are smaller than the radii of curvature of the outer surfaces of the
pipe elements
outside of the grooves so that the projections fit within and engage the
grooves.
Methods of securing pipe elements in end to end relation comprise a sequential
installation process when mechanical couplings according to the prior art are
used. Typically,
the coupling is received by the technician with the segments bolted together
and the ring
gasket captured within the segments' channels. The technician first
disassembles the coupling
by unbolting it, removes the ring gasket, lubricates it (if not pre-
lubricated) and places it
around the ends of the pipe elements to be joined. Installation of the ring
gasket often
requires that it be lubricated and stretched to accommodate the pipe elements.
With the ring
gasket in place on both pipe elements, the segments are then placed one at a
time straddling
the ends of the pipe elements and capturing the ring gasket against them.
During placement,
the segments engage the gasket, the projections are aligned with the grooves,
the bolts are
inserted through the lugs, the nuts are threaded onto the bolts and tightened,
drawing the
coupling segments toward one another, compressing the gasket and engaging the
projections
within the grooves.
As evident from the previous description, installation of mechanical pipe
couplings
according to the prior art requires that the technician typically handle at
least seven individual
piece parts (and more when the coupling has more than two segments), and must
totally
disassemble and reassemble the coupling. Significant time, effort and expense
would be
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saved if the technician could install a mechanical pipe coupling without first
totally
disassembling it and then reassembling it, piece by piece.
Summary
The invention concerns a coupling for joining pipe elements. In one example
embodiment the coupling comprises first and second segments positioned end to
end
surrounding a central space for receiving the pipe elements. A spring assembly
joins a first
end of the first segment to a first end of the second segment. The spring
assembly biases the
segments away from one another. An adjustable attachment assembly joins a
second end of
the first segment to a second end of the second segment. The adjustable
attachment assembly
is adapted to draw the first and second segments toward one another and into
engagement
with the pipe elements.
In one example embodiment, the spring assembly comprises
a first boss projecting from the first end of the first segment and a second
boss projecting from
the first end of the second segment. The second boss is positioned adjacent to
the first boss.
A first fulcrum is positioned on the first boss and contacts the second boss.
The segments
pivot about the first fulcrum. A link extends between and capturing the first
and second
bosses.
An example embodiment may further comprise a second fulcrum positioned on the
second boss. The second fulcrum contacts the first fulcrum.
Another example embodiment comprises a first land positioned contiguous with
the
first fulcrum on the first boss and a second land positioned contiguous with
the second
fulcrum on the second boss. The first and second lands are oriented angularly
with respect to
a plane defining an interface between the first and second segments.
Further by way of example, the coupling may comprise a first head projecting
from
the first boss and a second head projecting from the second boss. The link
engages the first
and second heads for retaining the link to the bosses. In an example
embodiment the link
comprises a ring encircling the first and second bosses.
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By way of example the adjustable attachment assembly may comprises a first lug
attached to the second end of the first segment. A second lug is attached to
the second end of
the second segment and is positioned in facing relation with the first lug.
Each lug defines a
respective hole. A fastener extends between the first and second lugs. The
fastener is
.. received within the respective holes. The fastener is adjustable for
drawing the segments
toward one another against the biasing of the spring assembly.
In an example embodiment each of the first and second segments may comprises
first
and second channels positioned on opposite sides of the segments. Each of the
channels
extends between the ends of the segments and has a first floor and a second
floor facing the
central space. The first floor has a greater radius of curvature than the
second floor. First and
second retainers are positioned respectively in the first and second channels.
Each of the
retainers comprises a band having oppositely disposed ends. A plurality of
teeth are
positioned along one edge of the band. The teeth project toward the central
space. At least
one tab is positioned along an opposite edge of the band. The band overlies
the first floo.
The at least one tab overlies the second floor when the retainers are
positioned within the
channels. An example according to the invention may comprise a plurality of
tabs.
By way of example, a third channel is positioned between the first and second
channels in each of the segments. The third channels extend between the ends
of the
segments and facing the central space.
In an example embodiment, the teeth are oriented angularly with respect to a
line
extending radially from an axis arranged coaxially with the central space. In
a further
example, the at least one tab is oriented perpendicularly to a line extending
radially from an
axis arranged coaxially with the central space. Further by way of example, the
at least one tab
is offset from the band toward an axis arranged coaxially with the central
space. In a specific
example embodiment, the at least one tab projects toward the third channel.
In an example embodiment, a first aperture is positioned in at least one of
the
segments. The first aperture may be aligned with the first channel and provide
a line of sight
toward the central space. In an example embodiment the first aperture is
positioned between
the first and second segments. The the first aperture may comprise a trough
positioned at an
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interface between the first and second segments by way of example. A further
example
comprises a second aperture in at least one of the segments. The second
aperture may be
aligned with the second channel and provide a line of sight toward the central
space. The
second aperture may be positioned between the first and second segments and
may comprise a
trough positioned at an interface between the two segments for example.
In an example embodiment a ring seal is positioned within the third channels.
The
ring seal has an inner surface sized to receive the pipe elements and an outer
surface sized to
support the segments in spaced apart relation sufficient to permit insertion
of the pipe
elements into the central space while the segments are attached to one
another. Further by
way of example, the retainer bands may be sized to cooperate with the ring
seals to support
the housing portions in the spaced apart relation.
In another example embodiment, each of the first and second segments comprises
first
and second shoulders positioned on opposite sides of each of the segments. The
shoulders
extend lengthwise along the segments and project toward the central space. The
shoulders
define a channel therebetween. A first arcuate surface is positioned on the
first shoulder, and
a second arcuate surface is positioned on the second shoulder. The arcuate
surfaces face the
central space in this example. A plurality of projections may be positioned on
each of the first
and second arcuate surfaces. The projections project toward the central space.
In an example
embodiment, the first arcuate surface may have a first radius of curvature and
the second
arcuate surface may have a second radius of curvature wherein the second
radius of curvature
is less than the first radius of curvature.
In an example embodiment a ring seal is positioned within the channel. The
ring seal
has an inner surface sized to receive the pipe elements and an outer surface
sized to support
the segments in spaced apart relation sufficient to permit insertion of the
pipe elements into
the central space while the segments are attached to one another.
The invention further encompasses, in combination, a coupling and a first pipe
element. The coupling is for joining a second pipe element to the first pipe
element. In an
example embodiment, he coupling comprises first and second segments positioned
end to end
surrounding a central space for receiving the pipe elements. First and second
shoulders are
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positioned on opposite sides of each of the segments. The shoulders extend
lengthwise along
the segments and project toward the central space. A first arcuate surface is
positioned on the
first shoulder. A second arcuate surface is positioned on the second shoulder.
The arcuate
surfaces face the central space. A spring assembly joins a first end of the
first segment to a
first end of the second segment. The spring assembly biases the segments away
from one
another. An adjustable attachment assembly joins a second end of the first
segment to a
second end of the second segment. The adjustable attachment assembly is
adapted to draw
the first and second segments toward one another and into engagement with the
pipe
elements. The first pipe element comprises a rim projecting outwardly from the
first pipe
element and extending circumferentially. The rim is positioned in spaced
relation to an end of
the first pipe element. The rim engages the first shoulder and is captured
within the central
space.
In an example embodiment the rim is defined by a circumferential groove in the
first
pipe element. In another example embodiment the rim is defined by a
circumferential bead
which projects radially outwardly from the first pipe element.
In an example embodiment the spring assembly comprises a first boss projecting
from
the first end of the first segment. A second boss projects from the first end
of the second
segment and is positioned adjacent to the first boss. A first fulcrum is
positioned on the first
boss and contacts the second boss. The segments pivot about the first fulcrum.
A link extends
between and capturing the first and second bosses.
An example embodiment may further comprise a second fulcrum positioned on the
second boss. The second fulcrum contacts the first fulcrum. A first land may
be positioned
contiguous with the first fulcrum on the first boss, and a second land may be
positioned
contiguous with the second fulcrum on the second boss. The first and second
lands are
oriented angularly with respect to a plane defining an interface between the
first and second
segments. In another example embodiment of a combination according to the
invention, a first
head projects from the first boss, and a second head projects from the second
boss. The link
engages the first and second heads for retaining the link to the bosses. In an
example
embodiment the link comprises a ring encircling the first and second bosses.
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In an example embodiment of the combination, the adjustable attachment
assembly
comprises a first lug attached to the second end of the first segment. A
second lug is attached
to the second end of the second segment and is positioned in facing relation
with the first lug.
Each lug defines a respective hole. A fastener extends between the first and
second lugs. The
.. fastener is received within the respective holes. The fastener is
adjustable for drawing the
segments toward one another against the biasing of the spring assembly.
In a further example embodiment the combination comprises a channel positioned
between the first and second shoulders in each of the segments. The channels
extend between
the ends of the segments and face the central space. Further by way of
example, a ring seal is
positioned within the channels. The ring seal has an inner surface sized to
receive the pipe
elements and an outer surface sized to support the segments in spaced apart
relation sufficient
to permit insertion of the second pipe element into the central space while
the segments are
attached to one another and the first pipe element is captured within the
central space.
A plurality of projections may be positioned on each of the first and second
arcuate
surfaces in an example embodiment of the combination. The projections project
toward the
central space. An example embodiment may further comprise at least one
aperture in at least
one of the segments. The at least one aperture may be positioned between the
first and second
segments. In an example embodiment, the at least one aperture comprises a
trough positioned
at an interface between the first and second segments.
The invention also encompasses a method of assembling the combination coupling
and pipe element. In one example embodiment the method comprises.
positioning the first pipe element with the rim engaged with the first
shoulder
of the first segment;
engaging the first end of the first segment with the first end of the second
.. segment to form the spring assembly;
supporting the first and second segments in spaced apart relation sufficient
to
permit insertion of the second pipe element into the central space while
capturing the first
pipe element within the central space;
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attaching the second end of the first segment to the second end of the second
segment using the adjustable attachment assembly.
Further by way of example, the method may comprise:
engaging the first pipe element with a ring seal;
positioning the ring seal within a channel defined by the first and second
shoulders of the first segment.
By way of example, the method may further include supporting the first and
second
segments in spaced apart relation sufficient to permit insertion of the second
pipe element into
the central space while capturing the first pipe element within the central
space comprises
support the segments on a ring seal positioned within a channel positioned
between the first
and second shoulders in each of the segments.
In an example embodiment, engaging the first end of the first segment with the
first
end of the second segment to form the spring assembly may comprise:
joining a first boss projecting from the first end of the first segment with a
second boss projecting from a first end of the second segment using a link,
and
contacting the second boss with a fulcrum positioned on the first boss.
Further by way of example, joining the first boss projecting from the first
end of the
first segment with a second boss projecting from the first end of the second
segment using the
link may comprise inserting the projections within a ring such that the ring
surrounds the
bosses.
In another example, attaching the second end of the first segment to the
second end of
the second segment using the adjustable attachment assembly may comprise
attaching a first
lug mounted on the second end of the first segment to a second lug mounted on
the second
end of the second segment using a fastener extending between the first and
second lugs.
In an example embodiment for joining the second pipe element to the first pipe
element, the example method comprises:
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with the segments attached to one another in spaced apart relation and with
the
rim of the first pipe element captured within the central space, inserting the
second pipe
element into the central space;
engaging the second pipe element with the ring seal;
drawing the segments toward one another using the adjustable attachment
assembly.
An example method may further comprise engaging the first and second arcuate
surfaces with the first and second pipe elements respectively upon drawing the
segments
toward one another. An example method may further comprise engaging
projections on the
first and second arcuate surfaces with the first and second pipe elements
respectively upon
drawing the segments toward one another.
In an example embodiment, the drawing the segments toward one another using
the
adjustable attachment assembly may comprise:
tightening a fastener extending between first and second lugs, the first lug
being
attached to the second end of the first segment, the second lug being attached
to the second
end of the second segment and positioned in facing relation with the first
lug, the fastener
being adjustable for drawing the segments toward one another against the
biasing of the
spring assembly.
By way of example, a method further comprises:
observing, through an aperture in at least one of the segments, whether or not
the second pipe element is present within the central space;
adjusting a positions of the second pipe element within the central space if
the
second pipe element is not present within the central space; and
drawing the segments toward one another once the second pipe element is
observed to be present within the central space.
Brief Description of the Drawings
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Figure 1 is an isometric view of an example embodiment of a pipe coupling
according
to the invention;
Figure lA is an isometric view of a portion of the example pipe coupling shown
in
Figure 1;
Figure 2 is an axial view of the example pipe coupling shown in Figure 1;
Figure 3 is a sectional view of the example pipe coupling shown in Figure 1;
Figure 4 is a partial sectional view of the example pipe coupling shown in
Figure I;
Figure 5 is an isometric view of a component used in an example coupling;
Figure 6 is a partial sectional view of the example pipe coupling shown in
Figure I;
Figure 7 is a sectional view of the example pipe coupling shown in Figure 1;
Figure 8 is an end view of the example pipe coupling shown in Figure 1;
Figure 9 is an exploded isometric view of an example preassembled combination
coupling and pipe element according to the invention;
Figure 9A is an isometric view of the example combination of Figure 9 shown in
a
preassembled state;
Figure 9B is a sectional view of the example combination shown in Figure 9;
Figure 9C is an axial view of the example combination shown in Figure 9;
Figures 10 and 11 are sectional views of the example combination shown in
Figure 9
illustrating assembly of a pipe joint; and
Figure 12 is a sectional view of an example preassembled combination coupling
and
pipe element.
Detailed Description
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An example embodiment of a coupling 10 according to the invention is shown in
Figures 1 and 1A. Coupling 10 is for joining pipe elements and comprises first
and second
segments 12 and 14 positioned end to end surrounding a central space 16 for
receiving the
pipe elements. A spring assembly 18 joins a first end 20 of first segment 12
to a first end 22
of the second segment 14. The spring assembly 18 biases the segments 12 and 14
away from
one another toward or into an open, pre-assembled state shown. When in this
open or pre-
assembled state, pipe elements can be inserted into the central space 16
without disassembling
the coupling 10 as described below.
The example spring assembly 18 shown in Figures 1 and 2 comprises a first boss
24
projecting from the first end 20 of the first segment 12, and a second boss 26
projecting from
the second end 22 of the second segment 14. The second boss 26 is positioned
adjacent to the
first boss 24. Bosses 24 and 26 are cantilevers and thus are substantially
responsible for the
biasing force of the spring assembly 18 as described below. A first fulcrum 28
is positioned
on the first boss 24, the first fulcrum 28 contacting the second boss 26 and
providing an axis
30 about which the segments 12 and 14 may pivot. In this example embodiment a
second
fulcrum 32 is positioned on the second boss 26. The second fulcrum 32 contacts
the first
fulcrum 28 to further define the pivot axis 30 about which the segments 12 and
14 pivot. First
and second fulcrums 28 and 32 are defined in this example embodiment by first
and second
lands 34 and 36 The first and second lands 34 and 36 are respectively
positioned on the first
and second bosses 24 and 26, the first land 34 being contiguous with the first
fulcrum 28, and
the second land 36 being contiguous with the second fulcrum 32 (when present).
At least the
first land 34 is oriented angularly with respect to a plane 38 comprising the
interface between
the first and second segments 12 and 14. In this example embodiment both the
first and
second lands 34 and 36 are angularly oriented with respective orientation
angles 40.
A link 42 extends between the first and second bosses 24 and 26. Link 42
captures the
bosses, while permitting pivoting motion of the segments 12 and 14. In this
example the link
42 comprises a ring 44 which encircles the first and second bosses 24 and 26.
Ring 44 is
retained on the bosses 24 and 26 by engagement with first and second heads 46
and 48
respectively projecting from the first and second bosses 24 and 26. Ring 44
and the bosses 24
and 26 cooperate to provide the spring biasing action of the spring assembly
18. The
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thickness 50 of the ring 44, the distance 52 between the fulcrums 28 and 32
and the point
where the bosses 24 and 26 engage the ring 44, along with the area moment of
inertia of the
bosses, are parameters which will establish the spring constant of the spring
assembly 18 and
thus determine the amount of force necessary to close the coupling 10 and
effect a joint. The
angular orientation 40 of the lands 34 and 36 and the distance the fastener 70
has been
tightened each act to set the maximum limit of separation between the segments
12 and 14,
and the inner diameter 54 of the ring 44 determines the minimum separation of
the segments
when supported by an undeformed spring assembly 18 as shown in Figures 1 and
2. In one
embodiment, the angular orientation 40 is such that, if the fastener 70 is not
present (such as
during the assembly of the coupling by the manufacturer) bosses 24, 26 may be
brought near
enough together that the inner diameter 54 of ring 44 will clear heads 46, 48,
allowing ring 44
to be easily assembled over bosses 24, 26. Subsequent assembly and tightening
of fastener 70
to a pre-determined distance 71 (see Figure 2) acts to separate heads 46, 48
sufficient to retain
ring 44 behind heads 46 and 58 as described above. The ring inner diameter 54
may be sized
to hold the segments 12 and 14 in the open or pre-assembled state sufficient
to permit
insertion of pipe elements into the central space 16, or the diameter 54 may
be larger, and
permit the segments 12 and 14 to be supported in the open or pre-assembled
state by other
elements of the coupling as described below. In this situation the segments 12
and 14 will
have some angular free play as the segments are drawn toward one another to
close the
.. coupling, the spring assembly 18 not immediately coming into effect upon
pivoting of the
segments.
Segments 12 and 14 are drawn toward one another by an adjustable attachment
assembly 56. Attachment assembly 56 joins the second end 58 of the first
segment 12 to the
second end 60 of the second segment 14. Attachment assembly 56 is adapted to
draw the
segments 12 and 14 toward one another and into engagement with the pipe
elements as
described below. In this example the adjustable attachment assembly 56
comprises a first lug
62 attached to the second end 58 of the first segment 12, and a second lug 64
attached to the
second end 60 of the second segment 14 Each lug 62, 64 defines a respective
hole 66, 68
which receive a fastener 70 that extends between the lugs In this example
fastener 70
comprises a bolt 72 and a nut 74, which, when tightened, draw the segments 12
and 14 toward
one another against the biasing force of the spring assembly 18.
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As shown in cross section in Figure 3, each segment 12 and 14 comprises first
and
second channels 76 and 78 respectively positioned on opposite sides 80 and 82
of each
segment. The first and second channels 76 and 78 extend between the first and
second ends
20 and 58 of the first segment 12, and the first and second ends 22 and 60 of
the second
segment 14 (see also Figure 1). Channels 76 and 78 face the central space 16.
As shown in
detail in Figure 4, each channel 76, 78 (channel 78 in segment 14 being shown)
is defined by
sidewalls 84 and 86 positioned in spaced relation to one another. Each channel
76, 78
furthermore has first and second floors 88 and 90 located between sidewalls 84
and 86.
Floors 88 and 90 face the central space 16 and are arcuate in shape as they
extend between the
ends 20 and 58 and 22 and 60 of the segments 12 and 14. As shown in Figure 4,
first floor 88
is positioned closer to the side 82 of segment 14 and has a greater radius of
curvature 92 than
the second floor 90, which has a radius of curvature 94. As shown in Figure 3,
the channels 76
and 78 and the arrangement of their floors 88 and 90 are symmetric about an
axis 96
extending transversely through the coupling 10.
As further shown in Figures 3 and 4, the channels 76 and 78 each receive a
respective
retainer 98. Retainer 98 is shown in detail in Figure 5 and comprises an
arcuate band 100
having oppositely disposed ends 102 and 104 Band 100 thus forms a "split ring"
which,
when compressed radially will deform to a smaller radius of curvature (see
Figure 7). In
some embodiments, each band 100 is sized such that contact between bands 100
and the
respective segments 12 and 14 within channels 76 and 78 allow one or both
bands 100 to
support segments 12 and 14 in spaced apart relation as shown in Figure 1. A
plurality of teeth
106 are positioned along one edge 108 of band 78. Teeth 106 project from band
100 toward
the central space 16. As shown in Figures 3 and 4, teeth 106 are oriented
angularly toward
axis 96 with respect to a line 110 extending radially from an axis 112
arranged coaxially with
the central space 16. The angular orientation is advantageous for retaining
pipe elements as
described below.
As shown in Figure 5, at least one, but in this example embodiment, a
plurality of tabs
114 are positioned along an edge 116 oppositely disposed from edge 108. As
shown in Figure
4, the one or more tabs 114 are oriented substantially perpendicular to the
line 110 and are
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offset from the band 100 toward axis 112 arranged coaxially with the central
space 16. This
offset of tabs 114 permits them to overlie the second floor 90, and the band
100 to overlie the
first floor 88, when retainers 98 are properly received within respective
channels 76 and 78 as
shown in Figures 3 and 4. Proper assembly of the retainers 98 within the
channels 76 and 78
permits pipe elements to be inserted into a pre-assembled coupling 10 as
described below.
However, as shown in Figure 6, the channels 76 and 78 (78 shown) and the
retainers 98 are
sized such that if the coupling 10 is improperly assembled with the band 100
overlying the
second floor 90 and the tab or tabs 114 overlying the first floor 88, the
retainer's radius of
curvature is smaller and teeth 106 effectively prevent insertion of the pipe
element into the
central space 16 with the segments 12 and 14 in spaced apart relation in the
pre-assembled
state. This cooperation between the retainer 98, its tabs 114, teeth 106, and
the first and
second floors 88 and 90 of channels 76 and 78 prevent improper assembly of a
pipe joint
using coupling 10. If the pipe elements could be inserted with the retainer
teeth 106 facing in
the wrong direction (Figure 6) then the teeth will not be self-actuating
against forces which
would draw or push the pipe element out of the coupling. Thus the retainer
would provide
reduced mechanical restraint.
As shown in Figure 3, segments 12 and 14 further comprise a third channel 118
Channel 118 is positioned between the first and second channels 76 and 78 and
faces the
central space 16. Channel 118 receives a ring seal 120 which ensures a fluid
tight joint. Ring
seal 120 is formed of a flexible, resilient material such as EPDM or other
rubber compounds
and has inner surfaces 122 sized to receive pipe elements when they are
inserted into the
central space 16 as described below. A pipe stop 124 is positioned between
inner surfaces
122. The pipe stop projects into the central space 16 and limits insertion of
pipe elements by
engaging the pipe elements when they are inserted into coupling 10 to the
desired depth. Ring
seal 120 also has an outer surface 126 that may be sized to engage and support
the segments
12 and 14 in spaced apart relation as shown in Figures 1 and 3. One or more of
the bands 100
may also cooperate with the ring seal 120 to support the segments 12 and 14 in
spaced apart
relation. The separation of the segments 12 and 14, when supported by the ring
seal 120
and/or band or bands 100, is sufficient to permit pipe elements to be inserted
into the coupling
when it is in its pre-assembled state (Figures 1, 2 and 3). Figure 3 shows an
example channel
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configuration wherein the second floors 90 are positioned between the first
floors 88 and the
third channel 118. In this example the tabs 114 project toward the third
channel 118 when the
retainers 98 are properly oriented within the coupling 10.
As shown in Figure 1, coupling 10 further comprises a first aperture 128 in
segment
12. In this example embodiment aperture 128 is aligned with the first channel
76 and
provides a line of sight 130 toward the central space 16. In this example
embodiment,
aperture 128 is positioned at the interface 132 between segments 12 and 14 and
is formed as a
trough 134 in both segments 12 and 14. The troughs 134 in each of the segments
12 and 14
are aligned so that when the segments are drawn into engagement they provide a
view toward
the central space 16 to permit visual confirmation that the retainer is
present and that a pipe
element is present within the central space and seated at least past the
retainer. As shown in
Figure 1A, a second aperture 136 is also positioned in at least one of the
segments 12 and 14.
The second aperture 136 is aligned with the second channel 78 in this
embodiment (see Figure
3) and also provides a line of sight toward central space 16. Again, in the
example
embodiment 10 illustrated, the second aperture 136 is positioned between the
segments 12
and 14. Aperture 136 is also formed by troughs 134 at the interface 132
between the
segments 12 and 14. The second aperture also permits visual confirmation that
a pipe element
is present within the central space 16.
As shown in Figures 1 and 3, each segment 12 and 14 also comprises first and
second
arcuate surfaces 138 and 140 respectively positioned on sidewalls 84 and 86.
Arcuate
surfaces 138 and 140 face the central space 16 and a plurality of projections
142 may be
positioned on each arcuate surface 138, 140. Projections 142 are arranged in
spaced relation
to one another along the arcuate surfaces 138 and 140 and project toward the
central space 16.
As described below, projections 142 engage the pipe elements and increase
joint stiffness and
accommodate a wider tolerance range on the pipe outer diameter.
When projections 142 are forced into engagement with the pipe elements as the
segments 12 and 14 are drawn toward one another they add stiffness to the
joint between the
coupling 10 and the pipe elements upon their engagement with the outer
surfaces of the pipe
Date Recue/Date Received 2021-04-13
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elements. Additionally, the projections 142 allow the coupling 10 to
accommodate a larger
pipe outer diameter tolerance in combination with known manufacturing
tolerances for
coupling 10. When the outer diameter of pipe elements is near the small end of
the tolerance
range the presence of the projections 142 ensures mechanical engagement
between the
coupling 10 and the pipe elements. However, when the pipe diameter is at the
large end of
the tolerance range the projections will tend to deform the outer surface of
the pipe elements
locally, and projections 142 may also deform. For couplings 10 used with plain
end pipe
elements this is particularly advantageous as plain end couplings are
typically designed so that
the arcuate surfaces 138, 140 (see Figure 3) do not engage the outer surfaces
of the pipe
.. elements. This arrangement ensures that the clamping force provided by the
fastener 70 (see
Figure 2) is fully applied to the retainers 98. Were the arcuate surfaces 138,
140 of the
coupling 10 to engage the pipe outer surface directly, the clamping force
would be divided
between contact of the arcuate surfaces with the pipe and contact between the
retainers 98 and
the pipe elements. Because the surface areas of projections 142 are small
relative to the
arcuate surfaces 138, 140, and contact the pipe element outer surface only at
discrete points,
only minimal clamping force from the fastener 70 needs to be diverted into
contact between
the projections 142 and the pipe elements to provide enhanced stiffness
without
compromising the axial retention provided by the retainers 98. Projections 142
are
advantageous in that they achieve greater rigidity even with the lesser
clamping force
available with the single fastener design of the coupling 10. The single
fastener 70 acts in
conjunction with the spring assembly 18 to ensure that adequate clamping force
is applied to
the pipe elements.
Operation of coupling 10 is illustrated in Figures 1, 3, 7 and 8. With the
coupling 10
in the pre-assembled state as shown in Figures 1 and 3, pipe elements 144 and
146 are
inserted into the central space 16. The pipe elements clear the teeth 106 of
retainers 98,
engage and the inner surfaces 122 of ring seal 120, and engage the pipe stop
124. Next, the
fastener 70 is tightened (see also Figure 2) drawing the segments 12 and 14
toward one
another. As shown in Figure 7 the ring seal 120 and the teeth 106 are
compressed between
the segments 12 and 14 and the pipe elements 144 and 146. Pivoting motion of
the segments
about fulcrums 28 and 32 (see Figure 2) is resisted by the biasing force of
the spring assembly
16
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18. As shown in Figure 8, the elements comprising the spring assembly, in this
example, the
bosses 24 and 26 and the ring 44, deform in proportion to the spring force,
with the ring 44
extending into an oval shape and the bosses 24 and 26 bending as cantilevers
(deformed
shapes shown in solid line, undeformed in broken line). Apertures 128, 136 may
be used to
visually confirm that the pipe elements are present in the coupling 10.
Figure 9 shows an exploded view, and Figure 9A shows an assembled view, of a
preassembled combination coupling and pipe element 147 according to the
invention. The
combination coupling and pipe element 147 comprises a coupling 148 and a first
pipe element
184, and is used to couple a second pipe element 186 to the first pipe element
(see Figures 10
and 11). The second pipe element 186 may, for example, be part of a piping
network (not
shown), and the first pipe element 184 may be part of another assembly, such
as a flexible
hose for a fire suppression sprinkler, or an inlet or and outlet of a pump or
a valve to cite a
few examples.
The coupling 148 comprises first and second segments 150 and 152 positioned
end to
end surrounding a central space 154 for receiving pipe elements. A spring
assembly 156 and
an adjustable attachment assembly 158, as described above for coupling 10,
join the ends of
the segments. Coupling 148 further comprises first and second shoulders 160
and 162 (see
also Figure 10) positioned on opposite sides 164, 166 of each segment 150 and
152.
Shoulders 160 and 162 extend lengthwise along the segments 150 and 152 and
project toward
the central space 154. Shoulders 160 and 162 define a channel 168 which
extends between
the ends of the segments 150 and 152 and faces central space 154. Channel 168
receives a
ring seal 170 for a fluid tight joint. Ring seal 170 has an inner surface 172
sized to receive
pipe elements (see also Figure 10) and an outer surface 174 which may be sized
to support the
segments 150 and 152 in the preassembled state, i.e., in spaced relation
sufficient to insert the
second pipe element 186 into the central space 154 without disassembling the
combination
147. Figure 9A shows the coupling in the preassembled state with the segments
150 and 152
in spaced relation. As described above for coupling 10, the spring assembly
156 may also be
used to bias the segments 150 and 152 into the open, preassembled state shown
in Figure 9A.
Ring seal 170 may also comprise a pipe stop 176 positioned between the inner
surfaces 172.
17
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Pipe elements inserted into the central space engage the pipe stop 176 when
properly seated
(see Figure 11).
As shown in Figures 9 and 10, each segment 150 and 152 further comprises a
first
arcuate surface 178 positioned on the first shoulder 160 and a second arcuate
surface 180
positioned on the second shoulder 162. Arcuate surfaces 178 and 180 face the
central space
154 A plurality of projections 182 may be positioned on the arcuate
surfaces 178 and 180.
Projections 182 are arranged in spaced relation to one another along the
arcuate surfaces 178
and 180 and project toward the central space 154. Projections 182 engage the
pipe elements
and increase joint stiffness and accommodate a wider tolerance range on the
pipe outer
diameter. As shown in Figure 9A, the coupling 148 may have at least one
aperture 171 in one
of the segments 150, 152. In this example the aperture 171 comprises a trough
173 positioned
at an interface between the first and second segments 150 and 152.
As shown in Figure 9, the first pipe element 184 comprises a rim 188 which
projects
outwardly from the first pipe element and extends circumferentially around.
Rim 188 is
positioned in spaced relation to an end 190 of the first pipe element 184, and
as shown in
Figures 9A and 10, is captured within the central space 154 by engagement with
the shoulder
162.
Rim 188 may be defined by a circumferential groove 192 in the first pipe
element 184, or a
circumferential bead 194 which projects radially outwardly from the first pipe
element 184.
In the example embodiment shown in Figure 9, the rim 188 is defined by both
the groove 192
and the bead 194.
The preassembled combination coupling and pipe element 147 shown in Figure 9A
in
its preassembled state is assembled as illustrated in Figures 9B and 9C. The
first pipe element
184 is engaged with the ring seal 170. The ring seal 170 is then positioned
within the channel
168 of the first segment 150 while the rim 188 is engaged with the first
shoulder 160 within
what will become the central space 154. Next the spring assembly 156 is formed
by engaging
the first end 175 of the first segment 150 with the first end 177 of the
second segment 152. In
the example shown, engagement of the first ends 175 and 177 is effected by
joining a first
18
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boss 179 projecting from the first end 175 of the first segment 150 with a
second boss 181
projecting from the first end 177 of the second segment 152 and pivotably
linking them
together using a link 183. In this example the link 183 comprises a ring 185
into which the
bosses 179 and 181 arc inserted, each boss having a respective head 187, 189
which retain the
bosses within the ring 185 when the segments are pivoted into the preassembled
state. As
shown in Figure 9C, the second boss 181 is contacted by a fulcrum 191 on the
first boss 179,
and the first boss 179 is contacted by a fulcrum 193 on the second boss 181.
The bosses 179
and 181 joined by the ring 185 act as cantilever springs which bias the
segments 150 and 152
away from one another and can also be used to support the segments in spaced
apart relation,
either alone or in combination with the ring seal 170 as described above. Next
the second end
195 of the first segment 150 is attached to the second end 197 of the second
segment 152
using the adjustable attachment assembly 158. In this example embodiment the
adjustable
attachment assembly comprises a first lug 201 mounted on the second end 195 of
the first
segment 150, a second lug 203 mounted on the second end 197 of the second
segment 152,
and a fastener 205 extending between the first and second lugs.
Working together with the spring assembly 156 (and/or the ring seal 170),
initial
tightening of the fastener 205 holds the segments 150 and 152 in the
preassembled state
shown in Figures 9A and 9C. In this configuration the segments 150, 152 are
supported in
spaced apart relation sufficient to permit the second pipe element 186 to be
inserted into the
central space 154 (see Figures 10-11) while also capturing the first pipe
element 184 by
engagement between the shoulder 160 and the rim 188. As shown in Figure 9C,
the
projections 182 increase the ability of the segments 150, 152 to retain the
first pipe element
184 when the combination 147 is in the preassembled state.
Figures 10 and 11 illustrate use of the combination 147 to join pipe elements
184 and
186. As shown in Figure 10, with the combination 147 in the preassembled state
the second
pipe element 186 is inserted into the central space 154. Upon insertion the
second pipe
element 186 engages with surface 172 on the ring seal 170 (the first pipe
element 184 is
similarly engaged with the ring seal). As shown in Figure 11, the segments are
then drawn
toward one another using the adjustable attachment assembly 158. In this
example the
fastener 205 is tightened, drawing the segments 150 and 152 against the
biasing force of the
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spring assembly 156 (see Figure 9C) and compressing the ring seal 170 to form
a fluid tight
joint. If projections 182 are present they engage the pipe elements 184, 186,
otherwise, the
arcuate surfaces 178 and 180 engage the pipe elements. Figure 11 shows the
arcuate surface
178 engaging a groove 192 in the second pipe element 186.
Figure 12 shows an embodiment of the preassembled combination 147 wherein the
first arcuate surface 178 has a first radius of curvature 207 and the second
arcuate surface 180
has a second radius of curvature 209. In this example embodiment the second
radius of
curvature 209 is less than the first radius of curvature 207. This
configuration of radii is
appropriate when rim 188 of the first pipe element is defined by a groove 192
because it
permits the first pipe element 184 to be captured by coupling 148 when it is
in the
preassembled state, while allowing the second pipe element 186 to be inserted
into the central
space 154 without disassembling the coupling. The groove 192 in the first pipe
element 184
may be deeper than the groove 192 in the second pipe element 186 to
accommodate this
embodiment.
The use of the combination 147 having a single fastener 205 and a captured
pipe
element 184 provides significant advantage by increasing the stability of the
coupling on the
pipe elements through engagement between the coupling shoulder and the rim of
the pipe
element. The presence of the spring assembly and single fastener significantly
inhibit the
ability to manipulate the coupling by rocking it, making it much more
difficult to separate the
pipe element from the coupling. The single fastener also simplifies the
tightening step, as
only one fastener need be tightened, as opposed to two fasteners, which must
be tightened in
an alternating sequence to avoid damage to the ring seal.
Couplings according to the invention are expected to improve the efficiency of
installation and the reliability of j oints formed. Further expected
advantages include a lighter
weight coupling which has a lower external profile and which is smaller for a
given pipe size.
Having only one fastener reduces the part count and contributes to reduced
errors during
assembly, as well as eliminating the need to tighten more than one fastener in
an alternating
sequence.
Date Recue/Date Received 2021-04-13
